Understanding Putting Geometry appears fairly simple and straightforward. Simple trig shows the basic error margins…
Assume a 1.68″ radius (one ball diameter) from the center of the cup, as the effective “drop zone”, where a ball traveling at a reasonable speed will certainly fall (velocity, rotation, slope, edge, etc. all play into that make/miss moment). Create a triangle with a 1 degree angle, and at what distance does the “1* error” factor start to matter? 96″. Eight Feet. So, at 8′, the player has a cone roughly 2* wide, or +/- 1*, in which to send the ball, and without (yet) considering other factors, make the putt.
Is +/- 1* very big? Take a look at the sweep second hand on a clock. One second (time) = 6*. Split that tiny “click” into six equal segments. It certainly isn’t much. We haven’t even taken into consideration all the elements that make up a putt’s true vector.
What does 1* look like, on a traditional Putter Face? Well, it’s not much. In fact, on a traditional putter, it should be just over 1/16th of an inch differential from heel to toe… except… it’s even worse than that.
Let’s examine a 32 foot putt. Your bilateral error margin (plus-minus) is rougly one-quarter of a degree (0* 15′), maximum. That’s only a tiny fraction of twist… so small no human can actually see it… it’s less than three sheets of paper thick equivalent in toe displacement. So forget being able to “consciously” control your putter-face at impact.
Now… here’s the real problem. Your putter doesn’t even “putt where it appears to aim”. That’s right. Even if you had lasers assisting your eyeballs, the apparent face angle and the actual angle are different… because your putterface is only true in one magic position, and you don’t know where that is. You couldn’t find it no matter what you do.
But… The Black Hawk & Black Swan… are designed to have the 2D and the 3D face angles always match. So your subconscious can “see” the line perfectly. You make way more putts. It’s a part of why we call our method… Putting 2.0.
Enjoy making putts.